Cosmetic compositions to deliver benefit agents are prepared by combining various oils and vehicles using various emulsifying systems.
Many consumers desire cosmetic products that have unique tactile properties during use and post-use. Specifically, such products should, upon application to the skin, deliver a high skin friction and a matte finish to overcome the oily skin feel and shiny skin appearance. The greater the increase in skin friction, the less greasy the user perceives the product to be. Vanishing cream bases which generally comprise fatty acids and alkali metal soaps are one of the preferred forms of such a cosmetically acceptable vehicle especially by consumers living in hot, humid climates, or consumers with oily skin.
More specifically, the typical sensory and optical features of these high skin friction and matte finish creams (vanishing creams) are to: 1) provide a dry, draggy, non-greasy, non-sticky feel to skin; 2) provide a non-shiny, matte finish; 3) spread easily on the skin; 4) absorb or “vanish” rapidly into the skin.
The traditionally used vanishing creams contain high levels of stearic acid and alkaline metal soap as an emulsifier, both of which are important to the physical stability & sensory properties of the product. The soap is usually formed by in-situ neutralization of a part of the total stearic acid with caustic potash or other alkali.
Unfortunately, however, many benefit agents e.g. acidic actives and sunscreens, are not chemically and physically stable in such vanishing creams that are largely based on fatty acids.
IN 190820, U.S. Pat. Nos. 5,827,508 and 5,759,524 (all to The Procter & Gamble Company) disclose photo-protective cosmetic compositions where in order to improve the chemical and photo stability of sunscreens, special materials such as surface treated zinc oxide are incorporated in the formulation. Whilst such formulations may be substantially free of fatty acids, unfortunately they lack the above-mentioned desirable sensory properties of a vanishing cream.
Thus we have identified that there is a need for a cosmetic base composition, which is free of stearic acid or other fatty acids and soap and yet maintains the sensory characteristics of a vanishing cream base. We have found that such a goal may be achieved by the careful selection of inorganic and organic agents emulsified with suitable emulsifier(s) and formulated with polymers.
It is thus an object of the present invention to formulate a cosmetic composition that is substantially free of fatty acids and soap and yet capable of providing the sensory characteristics of a vanishing cream.
It is another object of the present invention to formulate a cosmetic composition that is free of fatty acids and soap and is milder than a vanishing cream while providing the sensory characteristics of a vanishing cream.
It is yet another object of the present invention to formulate a cosmetic composition that is free of fatty acids and soap and in which a wide variety of benefit agents can be incorporated and that can stabilize benefit agents such as sunscreens and other acidic actives while providing the sensory characteristics of a vanishing cream.
It is yet another object of the present invention to formulate a cosmetic composition that is capable of enhancing the efficacy of both UV-A and UV-B types of sunscreen.